Seamless hollow body and method of making the same



Feb. 14, 1928.

J. -FABER sDAMDEss HoLLow BODY AND METHOD oF MAKING THE s'A'MD sheets-snee*` vFiled Aug. 25. 1 921 l l I llllklllll JW @maw/i@ Feb. 14, 192s.

J. FABER SEAML-ESS HOLLOW BODY AND METHOD O F MAKING THE SAME Filed Aug. 25. 1921 2 sweats-shew` 2 6" @ik ma@ um@ ATT?.

j Patented Feb, 14, 192s.

UNITED STATES .moon FABEm/r coLoeNE-oN-THE-RHINE, GERMANY.

SEAMLESS HOLLOW BODY AND METHOD OF MAKIG THE SAML penetreren mea August 25, 1921, serial Ne. 495,444, and in Germany December 1a,

(GRAN'lED UNDER THE PROVISIONS 0F TBE ACT 0F MARCH 3, 1921, 41 STAT. L., 1313.)

The present invention relates to the production of an improved article of manufacture which is capable of a variety of uses, such for instance as a protecting covering D for articles of merchandise which are susceptible to the action 'of water and air, a gas bag for balloons and similar pur oses, one of the objects of the invention eing to provide a hollow body which may be' ticle whereby the vapor pressure of the filmforming solution may be utilized to produceA a lm of uniform thickness.

, With the foregoing and other objects in view, which will appear as the -description proceeds, the invention consists in the novel procedure 'which will be hereinafter more full describedand particularly pointed out in t e claims.

In the drawings accompanying and forming part of this specification,

Fig. 1 is a side elevation of a cigar-protecting package in the form of a capsule made in accordance with the present invention; A Y

Fig. 2 is a side elevation of a modied form of cigar-protecting package;

Fig. 3 1s aside view of a protecting package made in the preferred form forcontaining granu Figs. 4 and 5 'are partly sectional, side elevations of a mold in which'a capsule similar to that shown in Fig; 1 may. be made, the two figures illustrating different positions of the parts at different process. Y

Organic, natural formations which are susceptible to damage'by the action ofvwater orfair, or which are Aliable toqui'ck deterloration, are often provided' by nature with protecting envelopes of thin film. Itis the -object of thepresent invention to imitate thisn-atural formation by producing a lilm 'lar or pulverized articles; and, Y

stages of the which may be used as an eifective protectmg covering for commercial articles which are liable to be damaged by moisture and air, and which'covering can be manufactured at small cost.

- In the manufacture of thepackage herein described, materials are usted which are soluble in a volatile solvent and which upon evaporation of the solvent, form a thin, transparent il'm. I have discovered that cellulose derivatives, such as cellulose ester, acetate, copper oxide cellulose of ammonia, formyl cellulose, viscose (Xantogenathas well as benzoate acetate, or nitrate of .cellulose'may be used to advantage. Chemically Y pure cellulose produced by the well-known method of coagulation from a solution of viscose mayl -b`e used if desired. Acetyl ce1 lulose, however, has Vproved most satisfactory, since the thinnest films can be produced therefrom, which even at a thickness of 1/100 millimeters is entirely sufficient for the purposes of the present invention." 'iNi-; tro cellulose should be used only whensuiiicientlydenitrated, because of itsliniiainma# ble character. If a quantity of acetone, or

` benzol,or equivalent solvent, is placed infaf Avessel and the latter is made airtight a-'considerable vapor pressure is developed :within the vessel due to the evaporation of the" solvent, and I have discovered that this vapor pressure can be made use of to great advantage in the formation of the hollow bodies forming invention, because it prevents the formationof blisters, air bubbles, etc. The essential features of the process, therefore, consist in using a volatile solvent and' so manipulating it as to produce a maximum vapor pressure, which effect is accomplished by the exclusionof atmospheric air from the vessel in which the article is being formed.

The new method consists substantially in distributing the .solution under the action of the vapor pressure generated by theAsolvent, on the walls of a suitable form or mold in an air-tight room, which room may be under normal atmospheric pressure or may be under vacuum. By this means it is possible to produce hollow bodies of uniform thickness .without blisters and less than 1/100 millimeter in thickness.

The 'following is anexample of the manthe subject matter of the present ner of carrying out the improved process,

.reference being had to the accompanying drawin s. s

A solution of a cellulose derivatiye, for example acetyl cellulose, in a volatile solvent, such, for instance, as acetone, or a solution of a cellulose derivative in b enzol is poured into a hollow mold, suchffor instance as-the mold A shown in Fig. 4, care being taken that such mold is perfectly dry since otherwise the resulting lm is like y to become turgid. A second hollow mold B, the open end of which is adapted to fit over the open end of the mold A, is then placed in position on said mold A, the joint between the molds A and B being as nearly airtight as possible. The molds are then inverted, that is to say, the mold B becomes the lowermost, so that the solution passes from the mold A into the mold B, leaving a thin film on the inner wall of the mold 'A. Owing to the comparatively large quantity of solvent in the mold and the exclusion of `yair therefrom, the vapor pressure generated is high and assists materially in the formation of amperfect film on the wall of the mold A. The molds are then taken apart and the iilm or layer adhering to the mold A is allowed to dry. A second mold A msysf then be fitted to the mold B and the mol inverted so that the new mold A becomes the lowermost, whereupon the mold B may be removed and its film' allowed to dry. second mold B being fitted to the new mold A .and the process 'of inversion continued until all of the solution has been used. After all of the molds have been coated on their inner walls with film and the solvent evaporatedfthe lms can readily be lifted from the molds without injury. As hereinbefore stated, the process must be carried on either inl a vacuum or in an airtight room, and care must be taken that the admission of air takes place evenly until the film has competely set, because under such conditions the vapor pressure generated, by the solvent acts on the film to produce a uniform thick- 11888.' l

A very importantV advantage in the usenof this process is that no medium, such as oil, talcum, o the like, is necessary to permit separation of the film from the-molds,"be cause after the solvent has evaporated, the skin or film formed on the wall of the mold can readily be removed therefrom.

For manufacturing capsules, such as that above described, on a large scale, a number of forms ma. be secured on a single frame, which may e placed within a container whichis closed to the atmosphere andpartly filled with. the solution.4 The form lled with solution may then be dro ped, where u on the va r pressure in tlie container c amber wil exert its force on the films produced on the forms, thereby forming 1/100 millimeter sides o `to manufacture,

films of uniform thickness. Other methods of carrying out the process will readily suggest themselves to the manufacturer. In a l cases, however, care must be taken to exclude the air during the operation of the pressure effect of the solvent, since otherwise light blisters are likely to be formed and the thickness of' the film will not be uniform. If desired, a suitable neutral gas may be used for drying the hollow ilm bodies instead of permitting them to dry in the open air.

Hollow bodies of greater thickness may be formed by producing several successive layers of film, either of the saine or different chemical ingredients, but the ingredients used must be such as are soluble in alvolatile solvent. Colors may also be added to the solution, as well as any suitable materials for increasing or decreasing the suppleness of the film. Y

The force of the vapor pressure may be regulated in any suitable manner. The length of time necessary to complete the process is dependent upon this regulation, while the thickness of the film is dependent upon the degree'of force exerted by the vapor pressure and the length of time during which such force is in operation. It, there fore, follows that the operator can readily control both the thickness of the film and the time consumed in carrying out the process.

The materials from which the molds are to be made should be chosen with a view to obtaining a surface to which the solution will not readily adhere, such for instance as glass or polished metal. The smoothness of the walls of the molds will aii'ect the transparency of the hollow bodies.

When it is desired to use the hollow bodies for advertising purposes, the desired advertisin matter may be engraved on the infg the molds or forms and, of course, will be reproduced on the film. The cost of printing the films is thus eliminated and' the further Cadvantage is obtained that the films can be marked with the trade-marks, prices, etc., of the goods which they enclose. v

A proteetlfig envelope made as herein described is particularly well adapted for use with articles of food', tobacco manufactures, chemical and pharmaceutical products, etc., because of the fact that it will not im art to such articles any undesirable or orei n smell. Moreover, because of the fact that tllle envelope may readily be removed om the article without injury, it may be repeatedly used. The envelope is extremely economical since a thousand complete capsules for cigars of average 'size can be produced from than 250 grams of acetylcellulose. The invention is, however, not limited to the use above set forth in thickness, 'made for in-Y but, Since. even a film ofi-- a solution-containing less ness, andtherefore could not becrumple without injury.

" bodies by immersing forms in a -pulverized material, a

lair-tight,

-out injury, and, moreover,

stance of acetylcellulose, is gas tight, the hollow bodies may be made of sufficient size to form balloonaand for such use the gastight quality and strength may be increased by forming the ilm of layers of chemically Adifferent ingredients, with an intermediate be interposed between the overlapping ends of any shape,

of the capsule. When an especially air-ti h t capsule is desired,this can be produced merely'vforming the iilm ofgreater thickness. q

As a container for tea, coffee, or cut tobacco, as well as bakingfpowder,

film of hollow spherical form, such for instance as that shown in Fig. 3, is preferable; A containerof this form, having a small opening which can'. be readily closed so as to renderthe container can be readily formed by the present process, and for this purpose it is preferable to usea lm formed of two or tliree layers of ditferentchemical compositionx. as above tight quality of the container.v Such layers, however, may be formed of cellulose acetate of different degrees of acetylation orjsolubilit or layers of caoutchouc or gutta-V pero ia may be alternated with layers of cellulose acetate, benzoate, nitrate, and so forth Heretofore it has been the practice l to wrap or roll tobacco products intin-oil, or

It is obviously im osto. enclose the pr uct in an airtight envelope suchas thatherein described, and, while I am aware that cellulose-containing materials,` suchas cardboard paper, have been used, tainer are usually held together by means ofan adhesiye and nor vwater proof, nor are such packages pliant or capable o being crumpled withare too expenslve.

The well-known transparent films of gelatine or celluloid could not he used for the purposes of this invention, because they would have to be made of considerable thlckin transparent paper. sible, in this manner Furthermore, gelatine is not waterprooLand celluloid always contains an odor oi camphor which it is impossible to remove therefrom.-

The manufacture of jointless hollow solution and thus forming a film on the outside of and similar `of material soluble in volatile solvents,

described, so as to increase the air#l the 'parts -o the con-v the package is neither air bodies,

d the bottom of the vessel,

the form is, of course, well-known. In the carryin out of such processes, however7 where t e hollow bodies are formed on the outside of the mold, the manufacture isrestricted to certain lforms, because in practice the thin hollow bodies cannot be removed from the mold without injury to the tilm'if, for instance, the mold is of spherical form. Moreover, even under such restricted use it is necessary to coat the surface of the mold with some material, such as talcum, oil, or grease, to prevent the ilm from sticking fast on said mold. This practice is objectionable, because the anti-adhesive material imparts a foreign odor to articles placed in the hollow ilm body. On lthe other hand, by means `of the present invention, the film can be formed on the inside walls-.of bodies and there is no necessity forl the use of any anti-adhesive on the wall of Sli the mold, because the film can readily be folded or crumpled without injury for fremoving it from the mold.

Having thus described what I claim is: -1. An article of manufacture, comprising av seamless hollow body formed of chemically diierent layers so disposed. that layers of cellulose derivatives alternate withlayer sai my invention,

hollow body being capable of being c rumpieds-without injury. Y

2. The rocess of manufacturing-hollow bodies which consists informingv a solution of a cellulose derivative in a volatile solvent,

, placing said solution in a mold so as to cover A the inner wall of`said mold, excluding 'atmospheric air from said mold, andpouring the solution into a second mold inrairtight'. communication with said first mold',

3. The process `of manufacturingz hollow 1 bodies, which consists in forminga of a cellulose derivative in a vv olatile solvent, lacing saidsolution in a hollow mold'thereyA to cover the inner wall of said mold, in-

vertin a second. mold over the open end of said rst mold therebyV to exclude atmospheric air from the molds, and inverting the position of the two molds.

4; The process of manuacturin'g hollow 'which consists in 'dissolving in volatile solvents a material adapted toform a skin. when the solvent is volatilized, pouring the solution intoa number of molds and placing the filled molds in an airtight vessel, 4manipulating the vessel and molds sosolution that the surplus of the 'solution collects at the layers of the solution sticking. tothe walls of the vmolds being exposed during the lprocess to 'the vapor pressure of the solvents bythe excluysion of the outer air thereby to cause the same to spread uniformly, and subjecting thelayers of solution in lthe molds to the action of the alr thereby to dry the same.

5. The process of manufacturing hollow bodies, which consists in dissolving in volatile solvents a material adapted to form a skin, placingsai'd solution 1n a number of molds and fastening these molds in an airtight vessel on a frame which is capable of being turned, turning the frame with the filled molds within the vessel so that the surplus of the solution trickles out of the molds, the

layers of the solution sticking to the inner' walls of the molds being exposed during the rocess to the vapor pressure ofthe solvents y the exclusion of the outer air thereby to vcause said layers to spread uniformly, and

admitting air into the vessel thereby to dry said layers.

6. The process of manufacturing hollow bodies, which consists in dissolving cellulose derivatives in volatile solvents, placing said solution in a number of molds fastened within a vessel on a frame which is capable of being turned, said vessel being capable of being closed airtight, turning said frame with the lilled molds thereon so that the surplus of the solution trickles out into the/vessel, the layers of solution sticking to the inner walls of the molds being exposed during the process to the vapor ressure of the solvents by the exclusion of t e outer air thereby toadhere to the surface of each of said molds,

excluding air from said vessel thereby to cause the vapor pressure of the solvent to exert pressure on said layers, and drying and removing said layers from the molds.

8. The process of manufacturing hollow bodies, which consists in dissolving acetylcellulose in aceton, placing the solution in a number of molds secured within a vessel onV a device capable of being turned, turning said device thereby to cause the solution to flow from said molds leaving only a layer thereof on the surface of each of the molds,

excluding air from said vessel thereby to cause the exertion of vapor pressure on said layers, and then subjecting said layers to the action of avdrying medium.

In testimony whereof I have signed my name to this specification.

JACOB FABER. 

